With the Girdle Y being 100%, the other dimensions are:
Crown height: 12%-16%
Crown angle: 34°-37°
Girdle thickness: 3.5%-4.5%
Pavilion depth: 42%-45%
Pavilion angle: 40.7°-41.7°
|Diamond Type Ia
||~2×10³ ppm of nitrogen – yellow
|Diamond Type Ia – Raman low / ultra low fluorescence
||~2×10³ ppm of nitrogen – white to light yellow
Almax easyLab is committed to its policy of continuous improvement. Specifications may change without notice. easyLab and Diacell are registered trademarks of Almax easyLab.
Almax easyLab can select its diamonds for low fluorescence. Standard measurements include laser excitation at 532 nm and covers fluorescence background in the range of 542 to 608 nm (Raman shifts between 1000 and 3000 cm-1). Measurements for different wavelength ranges can be made available on request. In special cases customers can select their own diamonds for low fluorescence using their own measurement set-up.
Almax easyLab classifies its diamonds with respect to fluorescence according to the following criteria:
- Type Ia UV low fluorescence – Checked with a UV lamp
- Type Ia Raman low fluorescence – The intensity of the two-phonon Raman transition at 2664 cm-1 is at least 1.25 times the intensity of the background fluorescence of diamond
- Type Ia Raman ultra-low fluorescence – The intensity of the two-phonon Raman transition at 2664 cm-1 is at least 2 times the intensity of the background fluorescence of diamond
All diamonds to be used for anvil manufacture are examined under a polarising microscope for birefringence. Diamonds with significant birefringence discontinuity, typical of inclusions, etc. are rejected. In addition diamonds can be selected for ultralow birefringence. Total birefringence is measured using crossed polarisers, a waveplate and matched to specifications. Normally:
- Low birefringence <0.0001
- Ultra low birefringence <0.00005
The modified brilliant diamond anvil design is derived from the traditional round brilliant cut used in jewellery. It developed as a way of maximizing back reflection and spectral dispersion, but is not necessarily the design which gives maximum strain.
How to chose the culet size ?
The culet size is to be decided as a function of the maximum pressure or the sample size. Typical sample space is given by the gasket thickness (typically 0.10 mm or less) and the central hole diameter (typically 30-50% culet size)
|Pmax (GPa) (*)
|Culet size (mm)
||< 0.20 mm, bevels up to 0.30 mm at 8°
(*) The Pmax values are only indicative. The maximum pressure achievable with a DAC is influenced by many others experimental parameters, like the gasket characteristics (material, thickness and hole size) or the pressure transmitting medium.
How the culet looks like?
||Culet with single bevel
||Culet with double bevel
Examples of typical requests for quote:
Diamond anvil, type Ia, Modified brilliant cut, 16-sided, 0.15 carat., culet of 0.10 mm, bevels up to 0.30 at 8°, (100)-oriented, Raman low fluorescence, low birefringence.
- Article nr.: P01029
- Quantity: 6 anvils.
Diamond anvil, type Ia, Modified brilliant cut, 16-sided, 0.25 carat, culet of 0.30 mm, (100)-oriented.
- Article nr.: P01032
- Quantity: 4 anvils.